Iowa Code § 28E.16: Election for bonds.

When bonds which require a vote of the people are to be issued for financing joint facilities of a county and one or more cities within the county, pursuant to an agreement made under the authority of this chapter, or pursuant to other provisions of law, the board of supervisors and the council of each city shall arrange for a single election on the question of issuing the bonds, but if the county and the cities are proposing to make separate bond issues, the ballot shall contain separate questions, one to be voted upon by all voters of the county, and one or more to be voted upon only by the voters of the city which is to make a separate bond issue. All elections on the question of issuing the bonds shall be held on the date specified in section 39.2, subsection 4, paragraph “d”.